Axial governor having a wide reed for stiffness in a circumferential direction



July 5 1966 E w. MOORMAN 3,259,711

AXIAL GOVERNOR HAVING A WIDE REED FOR STIFFNESS IN A CIRCUMFERENTIAL DIRECTION Filed Aug. 6. 1965 INVENTOR. Quail Edward William Moormou F|G.6 .06 mgw United States Patent Ohio Filed Aug. 6, 1963, Ser. No. 300,365 2 Claims. (Cl. 200-80) This invention is concerned with an improved speed regulating device or governor and it is more particularly concerned with a governor of the axial reed type for a small electric motor.

One-object of the invention is to provide a governor unit adapted to be employed in an electrical circuit to maintain the speed of a governed device at a pre-selected speed wherein the full component of centrifugal force is applied so as to provide increased sensitivity of governing action. A further object of the invention is to provide a centrifugal governor of the axial reed type wherein the sensitivity thereof is markedly increased in the lower speed ranges. A still further object of the invention is to provide a centrifugal governor employing an axially extending reed of such width as to provide stiffness in the circumferential direction.

These and further objects of the invention will become more readily apparent upon a reading of the description following hereinafter, and upon an examination of the drawings, in which:

FIGURE 1 represents a side view of the governor device of the invention;

, FIGURE. 2 represents a cross-sectional view taken along lines 2-2 of FIGURE 1;

FIGURE 3 represents a plan view of the reed like spring element employed in the embodiment of FIG- URES 1 and 2;

FIGURE 4 represents a cross-sectional view taken along lines 4-4 of FIGURE 2;

FIGURE 5 represents an exploded perspective view of the governor device of the invention; and

FIGURE 6 represents a schematic wiring diagram indicating the employment of the governor of the invention in connection with a small electric motor.

In referring to the drawings it is seen that the governor unit comprises a central shaft 2 of non-electrically conductive material upon which is mounted, as by a mold ing, a pair of disc-like members 4 and 6 which are made of electrically conductive material such as copper or a copper alloy. The shaft 2 has formed centrally therethrough the bore 8 and a somewhat reduced bore 10. The bore 8 is of such diameter as to enable the mounting of the governor unit upon the motor output shaft 12 of a motor 14, as shown in FIGURE 6 for example. The electrically conductive disc 4 is of a segmented nature in that it is cut off at a chordal surface 16. The governor device is mounted to the shaft 12 by a pair of plastic plugs 20 and 22 which are forced into engagement with the motor shaft 12 by a pair of set screws 24 and 26, respectively which are threaded into the threaded openings 28 and 30, respectively, formed in the disc 4. The plastic plugs 20 and 22 provide electrical insulation between the governor body 4 and the motor shaft. Under the pressure of the set screws 24 and 26 the plastic plugs will be deflected and flow into the screw threads so that after first assembly, the set screws may be loosened and the shaft removed without the plugs becoming loose or falling out.

The upper portion of the disc 4 has mounted centrally thereof a contact button 32 as by soldering. The contact 32 may be made of the usual electric contact materials and the disc 4 is further provided with the cut out areas 34 and 36 for the purposes as hereinafter described.

3,259,711 Patented July 5, 1966 Juxtaposed above the disc 4, yet within the same vertical plane, is a weight member 40 which is of electrically conducting material. The weight member 40 is conveniently formed in the shape of a segment of a disc so that (as clearly shown in FIGURE 1) it will normally assume a position whereby the members 40 and 4 present a substantially complete circular disc-like member. The weight or segment 40 has formed centrally therethrough a threaded opening 42 into which the contact screw 44 is threaded. The forward portion of the contract screw 44 has formed thereon the contact element 46 which preferably is of the same material as that of the first mentioned contact 32. The contact 46 may be positioned vertically by simply threading the screw 44 within the threaded hole 42. The under surface 50 of the weight 40 has a centrally cutout portion 52 to permit the contact screw 44 to extend towards the contact 32 without the possibility of interference with the reed-like spring 60.

As shown in FIGURES 3 and 5 the reed-like spring 60 is of relatively large width, the width being such as to substantially exceed one-half of the width of the disc 4 in order to provide circumferential stability or stiffness upon rotation of the governor unit. To effectuate the most reliable, accurate and durable governing action, the contact 46 should experience pure translational movement in a vertical path with respect to the axis of shaft 2. Where the customary narrow reed is employed (and referring to FIGURE 1), the contact 46 will experience a combination of translatory and oscillatory motion or roll about the longitudinal axis of the reed '60. This will cause the screw 44 to pivot on its contact 46 to the right or left, as viewed in FIGURE 1, depending upon the direction of rotation of the shaft 2. Although the disturbing forces are the same (i.e., torques about the axis of shaft 2), I have observed that the wide reed of the invention will dampen out and eliminate any tendency to rolling motion, whereas the narrow reed (even if it were supported by a wide weight 40) will still experience the undesired rolling motion. I have not been able to mathematically analyze or explain this phenomenon other than recording the observations made; and I am of the opinion that the restoring forces of the wider spring, which extend over a distance at least equal to /z the width of disc 4, will bring about the desired substantially pure translational vertical movement of contact 46 towards and away from contact 32. The series of holes provided in the reed 60 perform the following functions: the holes 62 and 64 permit the mounting of the spring reed 60 to the weight 40 as -by a pair of screws such as screw 66; whereas the holes 68 and 70 at the rear of the reed 60 permit the mounting to the disc 6 of the spring 60 as by a pair of screws such as screw 72. The hole permits free passage of the contact screw 44. When the screw 44 is rotated to travel vertically downwardly against the contact 32 the spring 60 is pre-loaded so that a greater centrifugal force is necessary to separate the two contacts, thereby permitting governing at higher .speeds. Upon rotating the screw 44 so as to travel vertically upwardly away from the contact 32 the pre-loading and hence the governing speed, is reduced. The disc 6 is formed of electrically conductive material as indicated above but has aflixed thereto or integral therewith the commutator segment 82, and is provided with a chordal surface 84 onto which the spring 60 is mounted.

An electrical lead is atfixed to the disc 4 and passes through an opening 93 in the shaft 2 and through the bores 8 and 10 towards the rear of the governor unit. The lead 90 further passes through a slot 92 and is soldered or otherwise aifixed as at 94 to the commutator segment 96. The commutator segments 82 and 96 are electrically separated as clearly shown in FIGURE 4, by the shaft material 2.

The arrangement of the surfaces 16 and 84 is such that the reed =60 lies in a plane substantially parallel to the axis of the shaft 2. Such construction enables a marked increase in sensitivity of the speed governor particularly in the lower speed ranges.

The governor of the invention maybe employed in a. circuit such as shown in FIGURE 6 wherein the armature of a motor 14 is shown, having the normal commutator means 100 and commutator brushes 102, 104. A source of DC power is indicated at 106 and flows over the line 108 towards one brush 102; the other brush 104 is connected to the brush 110-of the governor device which is in engagement with the commutator segments 82 and 96, alternatively. The other brush 112 of the commutator device is similarily engaged alternatively with the commutator segments 82 and 96. The lead114 extends from the brush 112 towards the DC. source 106. Usually a resistance is inserted in parallel between the governor brushes 110 and 112 (not shown). It is thus seen that when the speed of the motor shaft 12 increases to the point wherein the weighted spring reed assembly lifts the contact 46 fro-m engagement with the contact 32, the electrical circuit permitting power to flow to the brushes 102 and 104 will be broken, to accomplish the governing function. In the case where a resistance is employed, the power is decreased when the unit runs above desired speed.

Although a specific construction has been shown and described indicating a preferred embodiment of the invention, it is to be readily understood by those skilled in the art that many modifications may be made in the construction and arrangement of parts while still falling within the spirit and scope of the invention as set forth in the appended claims.

What I claim is:

1. A governor unit adapted to be employed in an electrical circuit to maintain the speed of a governed device at a preselected speed, comprising, in combination:

a shaft of electrically non-conductive material;

a pair of disc-like members of electrically conductive material spacedly mounted upon said shaft and extending in a radial direction from said shaft;

a weight arranged to lie substantially in the same plane as one of said disc-like members and juxtaposed thereto;

spring means anchored to the other of said disc-like members and attached to said weight for urging same towards said one disc-like member, said spring means comprising a reed-like element extending out of said plane and in a direction substantially parallel to said shaft;

a first contact member mounted upon said first one of said disc-like members and in electrical communication therewith;

a second contact member mounted upon said weight and juxtaposed to said first contact member;

said second contact member being in electrical communication with said other disc-like member; and

commutator means mounted upon said shaft and comprising at least two commutating surfaces, one such surface being in electrical communication with said first contact and the other such surface being in electrical communication with said second contact, said contact members and the center of gravity of said weight being arranged along a diametric plane of said one disc member, and said reed-like elements having a width greater than the radius of said one disc member, in order to provide stiffness in a circumferential direction to said unit; whereby when said governor unit is operatively assembled to a governed device and rotated therewith, the full component of centrifugal force is applied against the weight and spring means thereby providing increased sensitivity of governing action. 2. A governor unit adapted to be employed in an electrical circuit to maintain the speed of a governed device at a preselected speed, comprising, in combinationz a shaft member having non-conductive portions thereon,

a rotative member mounted on a non-conductive portion of said shaft and extending in a direction radially away from its rotating axis,

a movable mass juxtaposed to said rotative member and arranged to lie substantially in the same plane as said rotative member;

spring means mounted at one end to said shaft having 'said mass affixed thereto at its other end for urging same towards said rotative member, said spring means comprising a reed-like element extending out of said plane and in a direction substantially parallel to said rotating axis;

contact means mounted on said rotative member, and

contact means mounted upon said weight juxtaposed to said rotative member mounted contact means,

both of said contact means and the center of gravity of said movable mass being arranged along a diametric plane of said rotative member, and said reed-like element at least at the location of said diametric plane having a width greater than at least half the width of said rotative member measured in the radial direction away from its rotating axis in order to provide stiffness in a circumferential direction to said unit;

whereby when said governor unit is operatively assembled to a governed device and rotated therewith, the full component of centrifugal force is applied-against the weight and spring means thereby providing increased sensitivity of governing action.

References Cited by the Examiner UNITED STATES PATENTS BERNARD A. GILHEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner. I

H. A. LEWITTER, Assistant Examiner. 

2. A GOVERNOR UNIT ADAPTED TO BE EMPLOYED IN AN ELECTRICAL CIRCUIT TO MAINTAIN THE SPEED OF THE GOVERNED DEVICE AT A PRESELECTED SPEED, COMPRISING, IN COMBINATION: A SHAFT MEMBER HAVING NON-CONDUCTIVE PORTIONS THEREON, A ROTATIVE MEMBER MOUNTED ON A NON-CONDUCTIVE PORTION OF SAID SHAFT AND EXTENDING IN A DIRECTION RADIALLY AWAY FROM ITS ROTATING AXIS, A MOVABLE MASS JUXTAPOSED TO SAID ROTATIVE MEMBER AND ARRANGED TO LIE SUBSTANTIALLY IN THE SAME PLANE AS SAID ROTATIVE MEMBER; SPRING MEANS MOUNTED AT ONE END TO SAID SHAFT HAVING SAID MASS AFFIXED THERETO AT ITS OTHER END FOR URGING SAME TOWARDS SAID ROTATIVE MEMBER, SAID SPRING MEANS COMPRISING A REED-LIKE ELEMENT EXTENDING OUT OF SAID PLANE AND IN A DIRECTION SUBSTANTIALLY PARALLEL TO SAID ROTATING AXIS; CONTACT MEANS MOUNTED ON SAID ROTATIVE MEMBER, AND CONTACT MEANS MOUNTED UPON SAID WEIGHT JUXTAPOSED TO SAID ROTATIVE MEMBER MOUNTED CONTACT MEANS, BOTH OF SAID CONTACT MEANS AND THE CENTER OF GRAVITY OF SAID MOVABLE MASS BEING ARRANGED ALONG A DIAMETRIC PLANE OF SAID ROTATIVE MEMBER, AND SAID REED-LIKE ELEMENT AT LEAST AT THE LOCATION OF SAID DIAMETRIC PLANE HAVING A WIDTH GREATER THAN AT LEAST HALF THE WIDTH OF SAID ROTATIVE MEMBER MEASURED IN THE RADIAL DIRECTION AWAY FROM ITS ROTATING AXIS IN ORDER TO PROVIDE STIFFNESS IN A CIRCUMFERENTIAL DIRECTION TO SAID UNIT; WHEREBY WHEN SAID GOVERNOR UNIT IS OPERATIVELY ASSEMBLED TO A GOVERNED DEVICE AND ROTATED THEREWITH, THE FULL COMPONENT OF CENTRIFUGAL FORCE IS APPLIED AGAINST THE WEIGHT AND SPRING MEANS THEREBY PROVIDING INCREASED SENSITIVITY OF GOVERNING ACTION. 